is a growing trend in North America toward use of controllers and electronic
expansion valves on refrigeration cases.
need for energy efficiency and the desire for intelligent energy efficiency
have created a hunger for data. This trend started 10 years ago (or more) in
the building controls industry and is now being seen in the refrigeration
Data, when properly aggregated and normalized, can create a knowledge base from
which good decisions can be made. However, data for data’s sake is just like
buying random numbers in a lottery.
So, let’s discuss why data is so desired in the industry today and what
technological developments this desire for data is creating and driving.
think we would all agree that we are trying with great resolve to save energy.
But most of the low-hanging fruit in our buildings has already been picked such
as lighting retrofits and brick and mortar improvements like insulation,
windows, and installation of control systems. So now we need to become more
intelligent in order to get to the enticing fruit that is up higher in the
tree. Data can be the ladder to that fruit.
By gathering data on our building’s (and building system’s) performance, we can
identify hidden areas needing improvement. This drives the development of new
algorithms in our refrigeration control systems. That refrigeration technician,
who in the past was busy installing new valves and pressure regulators, is now
working with things like:
• Baselining, benchmarking and reporting
• Continuous commissioning processes
• Fault detection and diagnosis.
Sure, we are still driving efficiency through mechanical and electrical devices
also. There is a growing trend in North America towards the use of case
controllers (an application specific device that controls the condensing unit,
lighting, fans, compressors, defrost cycles, etc. in a refrigerated or frozen
case) and electronic expansion valves. These devices definitely provide an
energy savings, and the owner will justify the expense of these items through
the calculation of a return on investment.
However, the desire for these devices is often as much about getting data and
remote accessibility from the field bus as it is about efficiency. Having an
Internet accessible digital controller on your refrigeration rack, as well as
on each refrigerated case, has provided owners a new level of sophistication
and keeps feeding the data addiction.
let’s answer the basic question first: What are the owners getting from this
data? They are getting the power to make better decisions concerning their
refrigeration systems and their energy expenditures. Data - once aggregated and
normalized - becomes information. Information in the right hands can be very
powerful. So, for example, Danfoss Food Retail can take the raw data and
transform it into useable information (based on the customer’s needs) and place
that information onto a dashboard application that is available on a secure
website 24 hours a day, seven days a week. The dashboard application provides
graphical representation of their refrigeration systems performance, so it is
easy to digest and use.
these advanced tools, we can sustain the energy savings that we achieve during
retro-commissioning projects such as the Danfoss program called Continuous
Commissioning Processes. Everyone likes to achieve 20-30 percent energy savings
from a retro-commissioning of a supermarket, but it is even better to achieve
20-30 percent energy savings from a retro-commissioning project and then
sustain that savings over the next 10 years. Continuous commissioning allows
the sustainment of the savings by constantly monitoring and maintaining the
As we learned in Chemistry 101, entropy occurs naturally. If you don’t
explicitly maintain something, then chaos will degrade it. This rule applies to
everything, not just chemicals.
The analysis of system faults and the resultant identification of root causes
is another tool that can be deployed for the proper handling of data and
information. Again, through web-based systems, the supplier of such systems can
now act as a forensics team for customers and identify those anomalies that are
wasting energy in their refrigeration systems.
This is done by applying advanced algorithms in controllers that utilize domain
expertise in refrigeration and isolates clues to a coming problem. By
recognizing these clues, determinations can be made and announce, or remotely
fix, upcoming issues before they become a problem. This can save customers
money by avoidance of emergency maintenance calls and by sustaining energy
From a technology perspective, the ability to get to this
data and utilize it appropriately requires some pretty cool technologies. One
such technology from Danfoss Food Retail has been Industry Open Protocols.
Customers are demanding the ability to pull data and information, and in this
instance, data is available via XML attributes in controllers. This is in
addition to the ability to provide web access to supervisory
One objective of new energy efficient and intelligent controls is to allow
customers to succeed with their energy, sustainability, and compliance goals
well into the future. Data and information are the keys to this success.